Re: boring a timing gear (update)

UPDATE,

I bought a 24 tooth nylon gear (XL) with aluminum hub that was 1/4
inch bore.

I drilled it out to 3/8 and while trying to push it on the shaft, it
was a tight fit, not a press fit, the nylon seperated from the
aluminum hub.

I would expect that my first load on the unit would have been that
much force so that don't work.

I think I'll get a solid pulley and just use that.

McMaster only lists 1/4" ID's, anybody know who offers a good price
on 3/8 bore XL pulleys ?

Dave

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
>
>
> turbulatordude wrote:
>
> >I have a 24 tooth nylon timing gear that has a 1/2 dia aluminum
hub
> >thru the center and a 1/4 inch bore.
> >
> >I'd like to open it up to a 3/8 bore to fit my NEMA34 single stack
> >stepper to drive a 72 tooth pulley on my drill press.
> >
> >The setscrew is in a hub that is 0.875 inch dia so the screw will
> >have enought grab.
> >
> >I am not sure if the 0.062" wall is too thin.
> >
> >
> It depends on how much of a load you are going to put on it. If it
will
> be lightly loaded
> (by the setscrew, belt torque, and belt tension) it should work.
If you
> will be running it hard,
> it may swell the remaining hub and eventually cause the Nylon to
crack.
>
> Jon